Experiments Don’t Just Happen – They’re Designed

One of the biggest misconceptions students have about practical science is that experiments simply exist: you set them up, follow a worksheet, and out pops understanding.

In reality, good experiments are engineered.

Before a single measurement is taken, someone has had to:

• Decide what is being investigated

• Control which variables matter

• Test whether the equipment behaves as theory predicts

• Refine the method so results are clear, repeatable, and teachable

Making the Most of the Lascells Ltd Sonometer

I’m currently running a series of test experiments to make full educational use of the Lascells Sonometer. On paper, a sonometer is “simple”: a stretched wire, a pulley, masses, and a vibration source. In practice, getting results that genuinely help students see and understand the physics takes careful design.

The goal isn’t just to show that

frequency depends on length, tension, and mass per unit length

but to do it in a way where students can:

• Clearly observe nodes and antinodes

• Collect data that actually fits the expected relationships

• Understand why the graphs look the way they do

Iteration Is Where Learning Happens

Initial trials often reveal issues:

• Tensions that are too low to form clean standing waves

• Frequencies that sit awkwardly between harmonics

• Measurements that look noisy rather than meaningful

Each run feeds into the next:

• Adjusting string length ranges

• Refining mass steps

• Choosing frequencies that make harmonics obvious

This iterative process mirrors real scientific practice, not just exam-board physics.

Why This Matters for Students

When experiments are properly designed:

• Practical work reinforces theory instead of confusing it

• Students trust their data

• Graphs stop being abstract and start telling a story

It also teaches a deeper lesson:
science is not about following instructions – it’s about thinking.

That’s the mindset I want students to take away, whether they’re studying GCSE Physics, A-Level Physics, or heading towards practical science beyond school.